Power operated hacksaw



Qec. 5 19329. A. H. PNEUMAN POWER OPERATED HACKSAW 2 Siaeets-Sheei 1Filed July 14, 1957 INVENTOR. rffiwflfl fi ifh m n, mzz '0 WMVATTORNEYS.

5% 1939 A. H, PNEUMAN 2,182,234

POWER OPERATED HACKSAW Filed July 14, 1937 2 Sheets-Sheet 2 l N VE NTOR.

(2%]: up jfalla zdfizeumajz,

BY %W%% MV A TTORNEYS.

Patented Dec. 5 1939 UNITED STATES i ATENT OFFICE POWER OPERATED HAGKSAWArthur Holland Pneuman, Syracuse, N. Y.

Application July 14, 1937, Serial No. 153,570

5 Claims.

This invention relates to power'operated hacksaws, and more particularlyto a portable type which is bodily liftable and which may beconveniently taken to and used on the job or work after the manner ofother conventional portable power operated tools.

about by the operator.

The invention has as a further object, a saw of the type referred toembodying a particularly work.

The invention consists in the novel features and in the combinations andconstructions hereinafter set forth and claimed.

In describing this invention, reference is had to the accompanyingdrawings in which like characters designate corresponding parts in allthe views.

Figure 1 is a top plan view of a power operated hacksaw embodying myinvention.

Figure 2 is a side elevational view of the machine shown in Figure 1.

Figure 3 is an enlarged, sectional view taken on lines 3-3, Figure 1.

Figure 4 is an enlarged view taken on lines 44,

Figure 1.

The structure comprises a base member ID formed at one end with a flatportion II which is mounted the driving motor 12 and a switch 13 forcontrolling the operation of the motor.

The base ll] extends upwardly in angular relationship to the flatportion I, and the forward end thereof is formed with a horizontallyextending portion I4 supported by a leg i5, the lower end of which isarranged in alinement with the flat rear portion H of the base.

The base is also formed with a vertical portion I6 arranged intermediatethe angular extending portion and the horizontal portion I4, and whichvertically extending portion l6 constitutes the stationary jaw of a viseor work holder.

The movable jaw I! of the vise is supported by a screw l8 slidablymounted in a slot 19 formed in the horizontally extending portion M ofthe base. The jaw I1 is actuated toward and'from the stationary jaw l6by means of a screw 20 provided at its outer end with an operatinghandle 2 I. The stationary jaw is preferably formed with one or moretransversely extending V grooves 22 to receive circular work, such asthe tube 23. 1

The rear portion of the base is formed, or provided, with an upwardlyextending support member 24, to the upper end of which is pivoted an arm25 on a stud 26. The arm 25 extends forwardly of the base member and asaw frame 2'! is slidably mounted on the arm 25. The saw frame is ofconventional U shaped form, and provided L with conventionalmechanismfor holding a saw blade 28.

The arm 25 is of rectangular cross sectional formation, and the rearportion of the saw frame is provided with a complemental recess'toslidably receive the arm 25, and the open side of the recess is closedby a detachable plate 29. The opposite side of the saw frame is providedwith a slot or guide way 30 so arranged as to extend at an oblique angleto the arm 25, as illustrated by dotted outline Figure 2. provided withan upwardly extending support or bracket 32 arranged forwardly of therear portion II, and is formed with a transversely extending aperture inwhich a shaft 33 is journalled and which is provided at one end with acrank 34 having a pin 35 extending into and cooperating with the obliqueslot 3%! to effect reciprocation of the saw frame on the arm 25 uponrotation of the shaft 33. The shaft 33 is operatively connected to themotor 52. As here shown, the motion transmitting means, connecting theshaft 33 and motor i2, consists of a worm 35 secured to the motor shaft37? and arranged in mesh with a worm wheel 38 secured to the oppositeend of shaft 33.

During reciprocation of the saw frame 27, the arm 25 is permitted tomove about its pivot'26 and effect movement of the saw blade 28 towardand from the work 23. The outer or free end' of the arm 25 is providedwith a pin 49 cooperable with a guide member M secured to the stationaryjaw 15 of the work vise. The edge of the guide member 4|, confrontingthe pin 40, is formed arcuate about the pivot 26 of the arm 25 and isprovided with a stop at each end to limit the upward and downwardmovement of the arm 25.

Attention is called particularly to the angular The base member isarrangement of the guide slot 30, and because of the angular position ofthe same, the crank pin 35 is cooperable therewith to effect downwardmovement of the saw frame upon the rearward or cutting stroke of thesaw, and upward movement of the saw frame upon the forward or returnstroke thereof. That is, during the downward stroke the pin 35 is inengagement with the rear wall 43 of the guide slot 30, and during theforward stroke is in engagement with the forward wall 44, and because ofthe angular relationship of these'walls a vertical movement is impartedto the saw frame 2'! during reciprocation thereof. Means is provided foradjusting the downward and upward pressure effected by the cooperationof the crank pin and guide slot, which means is in the nature of afriction device carried by the saw frame 27.

The plate 29, see Figure 3, is provided with an internally threadedsleeve 85 to receive an adjusting screw 45 provided with a knurled head41. A-friction element or pad 43 is arranged to engage the side of arm25, and is provided with a stem 49 slidably mounted in sleeve 45. Ahelical compression spring 50 is interposed between the innerend ofscrew 56 and stem 49 and accordingly, by threading the screw 45 inwardlythe friction element 48 is pressed more firmly against the side of thearm 25. This increase of friction opposes the action of the crank andcrank pin 34, 35 and accordingly, increases the downward pressure duringthe cutting stroke, or, in other words, increases the feed on saw blade28. Because of the angular arrangement of the guide slot 30, a slightincrease in the frictional engagement between the saw frame 21 and arm25 is only necessary to produce an effective increase in the feed of thesaw and accordingly, no appreciable amount of power is lost due to thisincrease in friction.

Preferably means is also provided to prevent excessive pivotal movementof the arm 25 during the return stroke of the saw frame. That is, inpreventing the saw blade 28 from moving out of engagement with the worktoo great a distance during the return stroke of the blade which wouldresult in the blade dropping onto the work at the commencement of thecutting stroke. Thismeans is in the nature of a disk 55 secured to arm25 as by rivets 56, and is formed with a channel shaped flange 51, theupper edge 58 of the outer side of which is of arcuate formation, seeFigure 2, and the ends of the flange are bent outwardly to form stops59. The outer side of the flange 57, or the arcuate edge 58 thereof, iscooperable with-a hook shaped member 60 slidably mounted on the upperend of an adjustable member 6l pivotally mounted at its lower end to thebase If? on screw 52. The upper end of the member BI is provided with avertically extending slot 63 to slidably receive rivet 64 secured to thehook shaped member 60, and the hook shaped member 60 is yieldingly urgeddown wardly by a helical tension spring 65, the lower end of which ishooked about the screw 62. The upper end of member BI is formed withoutwardly extending ear portions 65 which serve as grip handles forconveniently adjusting the member about pivot 62, and likewise adjustingthe hook member 60 along the arcuate edge 58 of member 55. The flange 51extends transverselyof the vertical plane passing through the pivot ofarm 25 and accordingly, when member 6! is shifted forwardly, or to theleft Figure 2, arm 25 is yieldingly urged downwardly and accordinglyopposes upward movement of the arm 25 and saw frame 26 during the returnstroke of the saw.

The purpose of this structure is to yieldingly maintain the moving partsof the mechanism in engagement, and to prevent any vibration orchattering of the saw during cutting operation. Also, this mechanismyieldingly urges the saw frame and saw towards the work 23, and tends tolimit the upward movement of the saw from the work upon the returnstroke of the saw frame.

If desired, a friction washer may be inserted between the arm 25 and theupper end of the support or, as here shown in Figure 4, between the disk55 and the support 24. In this event, a nut H is threaded upon the outerend of stud 26 and is employed to compress the helical compressionspring 12 to move the arm and washer 10 into engagement with the support24.

The rear portion of the saw frame 27 is provided with a projection l3arranged to engage the actuating element 14 of the switch l3 when thesaw 28 has passed through the work and the pin 40 engaged the lower stopon guide member 4|. The switch is on when the actuating element 14 isin. the forward position as shown in Figures 1 and 2, and at the end ofthe cutting stroke immediately following the severance of the work, theelement 14 is moved into off position by the projection 13.

It will be observed that because of the relative arrangement andconstruction, the saw is exceptionally compact and conveniently handled.Pieces may be conveniently cut from the ends of bars projecting from thestock rack by simply clamping the vise onto the bar. The leg I5 isdetachable to permit the cutting end of the saw to be used in closequarters. Due to the compactness of the machine, it is particularlysuited for use on the workmans bench, and affords a convenient means ofquickly cutting a piece of work while the worker is free to do otheroperations.

What I claim is:

l. A power operated hacksaw comprising a base, an arm pivoted at one endto said base, a saw frame slidably mounted on said arm and beingprovided with a guide way extending at an oblique angle to said arm, ashaft journalled in the base and extending transversely of said arm andsaw frame, and being provided with a crank arranged in said guide Wayand cooperable to effect reciprocating movement of said saw frame onsaid arm upon rotation of said shaft, and means for effecting rotationof said shaft.

2. A power operated hacksaw comprising a base, an arm pivoted at one endto said base, a saw frame slidably mounted on said arm and beingprovided with a guide way extending at an oblique angle to said arm, ashaft journalled in P the base and extending transversely of said armand being provided at its end with a crank cooperating with said guideway to effect reciprocation of said saw frame relative to said arm uponrotation of said shaft, a friction element carried by said saw frame andengaging said arm, means for adjusting said element to vary the frictionbetween the saw frame and said arm, and a motor carried by the base andoperatively connected to said shaft.

3. A power operated hacksaw comprising a base member having a forwardlyextending projection, an arm pivotally mounted at one end to the rearportion of the base and extending forwardly, a saw frame slidablymounted on said 15 arm and a saw blade carried by said frame, a workvise mounted on the forwardly projecting portion of said base andarranged in juxtaposition to said saw blade, a shaft mounted on the baseintermediate its ends and extending transversely of said arm and beingprovided at one end with a crank, said saw frame being provided with aslot extending at an oblique angle to the axis of said arm, and saidcrank having a pin movable in said slot to effect reciprocation of saidsaw frame upon rotation of said shaft, a motor mounted upon the rearportion of the base and being operatively connected with said shaft toeffect rotation thereof.

4. A power operated hacksaw comprising a base, an arm movably mounted onsaid base, a saw frame slidably mounted on said arm and b ing providedwith a guideway extending at an oblique angle to said arm, a shaftjournalled in 20 the base and extending transversely of said arm with toeffect reciprocating movement of said saw frame on said arm uponrotation of said shaft, means cooperable with said arm and saw frame toyieldingly resist sliding movement of said frame on said arm, and meansfor effecting rotation of said shaft.

5. A power operated hacksaw comprising a base, an arm movably mounted onsaid base, a saw frame slidably mounted on said arm and being providedwith a guideway extending at an oblique angle to said arm, a shaftjournalled in the base and extending transversely of said arm and sawframe and being provided with a crank: arranged in said guideway andcooperable therewith to effect reciprocating movement of said saw frameon said arm upon rotation of said shaft, means carried by said saw frameand cooperable with said arm to yieldingly resist sliding movement ofsaid frame on said arm, and means for eifeoting rotation of said shaft.

ARTHUR HOLLAND PNEUMAN.

